Waukesha Bearings Tilting Pad Journal Bearings with Forced Lubrication - Manual (Page 2)

I. GENERAL DESCRIPTION
This is a tilting pad type journal bearing consisting of a number (generally five) of arcuate journal
pads retained within an annular shell and associated end plates. The bearing will accept radial load in
any direction and is particularly useful under high speed, light load conditions where bearing
instability may be encountered with other types of journal bearings.
Several basic types are produced, all based around the same journal pads. (These variations are shown
on page 4.) The differences in these basic types are in the housing seat configuration and whether a
thrust face is incorporated.
The journal pads are constructed so they are free to tilt in the bore of the shell. This action assists in
the generation of the hydrodynamic oil film at each pad and is basic to the inherent stability
characteristics of this type bearing.
II.
DETAILED DESCRIPTION
The journal pads consist of a steel backing on which has been centrifugally cast a babbitt layer. The
babbitt surface is bored to provide the desired “pad clearance” (C
p
) of the shaft diameter. The radial
thickness of the pad (at the pad center) is held close tolerance to establish the desired “bearing
clearance” (C
b
) when the pads are assembled to the housing. The relationship of “bearing clearance”
and “pad clearance” establishes the “bearing preload.”